Clyde's Garden Planner takes the guesswork out of when to plant the spring or fall vegetable garden. The planting dates are based on average frost dates shown on the paper slider or as an app for mobile devices.

When I met Clyde Majerus of Grovesping, Mo., I issued him a challenge. I told him I didn't think he could help me find the best vegetable planting dates in my challenging Zone 5 garden. Around here, spring temperatures can fluctuate from 80 degrees one day to snowing the next.

Clyde accepted my challenge as he showed me how to use his garden planning tool to find the best planting dates for all the crops I cared to plant.

Clyde's Garden Planner is a simple, inexpensive tool, but includes a wealth of information for gardeners all over the country. The chart uses the last average frost date for where you live. When you slide the red line to your area's average last spring (or first fall) frost date, the planting information falls into place.

The planner comes with a table that provides frost dates for cities throughout the continental U.S. and Canada.

In addition to the planting dates, Clyde's chart gives information on when to start seeds indoors, shows how many seeds and plants of each type fill a 10-foot row, details how deep to plant seeds, and provides the distance between plants. Estimated harvest dates are also included to keep gardeners on track.

When Clyde lined up Denver's last average spring frost on May 5, all the planting dates for crops from onions to pumpkins were clearly displayed. It looks like I can start planting my tomato and pepper plants on May 31.